Prior art removable multiple disc data storage packs typically are unable to adequately protect the data storage media from dirt and other debris which contaminate the surface of such media, causing data storage error and other operational difficulties. Such contamination usually arises during insertion of the disc pack into and removal thereof from the disc drive. For example, in some top-loading models, the bottom half of a canister-like cover must be removed outside of the clean-air atmosphere of the disc drive in order to permit installation of the disc pack into the drive and the read/write heads access to the media surfaces. Thus, prior art top-loading disc packs are not always enclosed by a protective canister, and dirt can contaminate the media as it is being installed into the drive. In some side-loading configurations, some portion of the canister protecting the disc media surface is hinged so that, as it is loaded into the drive, a door opens to permit the read/write heads access to the recording surface.
In addition to the inadequate protection of the media, prior art disc packs are inconvenient to use. The coupling between the disc pack and the drive spindle often requires substantial effort on the part of the operator to assure properly aligned engagement therebetween. As mentioned above, the cover may have to be removed for installation of the pack into the drive. Such cover must then be stored outside the drive and can collect dirt and other contaminants which can be transferred to the media when the covers are re-installed after the pack is removed from the drive.
A module for containing rotating data storage media such as disc packs, constructed according to the present invention, always capsulates the media in a dust sealed cartridge. The module can be installed into the disc drive without exposing the media to outside contaminants. The coupling between the disc pack and the drive motor spindle is provided by a magnetic chuck comprising a permanent magnet on the drive motor and chuck plate on the disc pack hub. The pack is located radially on the spindle motor nose cone by a disc pack hub flexure. The chuck plate is accessible to the permanent magnet on the drive motor by removing a cover. The cover is stored on top of the module when it is installed in the drive. When the module is not installed in the drive, the chuck plate cover is fastened in place by means of a quarter-turn fastener for easy removal and installation.
The cartridge of the media module of the present invention for housing the disc pack comprises a top cover, including a handle coupled to the disk pack hub assembly, and a bottom cover, having space for a removable chuck plate cover and having a sliding door mounted on a track for covering an opening in the side wall of the bottom cover which provides access to the media for filtered air and the read/write heads. The top cover of the cartridge also includes locating tabs which align the module in proper orientation for opening the sliding door as the module is rotated after insertion into the drive. The locating tabs also prevent inadvertent removal of the module during operation when the sliding door is open, thus minimizing contamination of the media surface and read/write heads.
When the carrying handle located in the top cover of the module is lowered into its installed or stored position, the magnetic chuck engages the hub of the disc pack with the motor spindle. When the handle is levered into the upright carrying position, the magnetic chuck releases the hub of the disc pack from the motor spindle and the entire module, including disc pack, may be counter-rotated and removed. As the module is rotated, the sliding door is closed automatically, thus minimizing exposure of the media surfaces to contamination by dirt and debris. Levering the carrying handle into the upright carrying position to remove the module from the drive also locks the disc pack hub firmly within the cartridge to prevent rotation and other movement of the media and resultant damage thereto within the module as the module is transported. After the module has been removed from the drive, the chuck plate cover is installed in position in the center of the lower cover of the module which, in turn, retains the locked position of the disc pack within the module when the carrying handle is lowered for storage of the module.